At present, as an epitaxial growth apparatus for causing an epitaxial film to grow, on a substrate using epitaxial growth, an apparatus including a process chamber and a rotatable substrate support disposed in the process chamber and configured to rotate a substrate about a rotation axis is known in which a reactant gas is introduced to the substrate in a direction parallel to the substrate to form a film on the substrate on the substrate support.
In such an epitaxial growth apparatus, there is currently a need for an increase in growth rate. However, it is not preferable that a large amount of source gas is included in the reactant gas so as to further increase the growth rate, for example, because an increase in the film formation cost or an increase in the number of particles is caused.
In epitaxial growth, when the thickness of a boundary layer (at a position at which the flow rate is 99% of the flow rate of the main stream of the reactant gas flow) on the surface of a substrate decreases, it is known that an increase in growth rate is expected. On the other hand, when the thickness of the boundary layer simply decreases, a flow in which the reactant gas escapes toward the circumferential edge of the substrate on the surface of the substrate is formed and it is thus difficult to adjust a film thickness distribution or a resistivity distribution.